palexy Offline Upload & Sell: Off
|
Joe,
Welcome to FM. You need the Quantum CKE cord to use the 2x2 with the sb900.
As far as whether the 2x2 or SC is better for you depends on what is important to you. According to the Quantum website (a very good source of information on all things Quantum), you should expect 700 flashes w/ a 1 sec. recycle with the 2x2 whereas the smaller, lighter, SC should give you 400 flashes with a 1.4 sec. recycle time.
The 2x2 can power 2 devices at once (e.g. 2 speedlights or one speedlight and 1 camera) whereas the SC can only power 1 device at a time.
I own the 2x2 and find that it does a great job powering my t5d, but for a SB900, you may be happier with less weight. Check out the www.qtm.com website. They have a "help me select a battery" type of function that may answer your question for you. The other thing you'll want to consider, of course, is whether exchanging your wife's gift will have a "chilling effect" on future photo-related gifts. If so, definately keep the 2x2! 
Paul
|